Matthew bentley and john bentley



(No Modl.) I'

4 M. 85 J. BENTLEY.

ARRYING PLUG 0R WEDGE. No. 374,574. Patented Dec. I3, 1887.

UNITED STATES PATENT OFFICE.

MATTHEW BENTLEY AND JOHN BENTLEY, OF DUDSWELL, QUEBEC, CANADA.

' QUARRYING PLUG R WEDGE.

SPECIFICATION forming part of Letters Patent No. 374,574, dated December 13, 1887.

' Application filed May12, 1887. Serial No. 137.990. (No model.)

To all whom it may concern:

Be it known that we, MATTHEW BENTLEY and JOHN BENTLEY, citizens of Canada, residing at Dudswell, in the county of Wolfe and Province of Quebec, Canada, have invented an Improved Quarrying-Plug; and we do hereby declare the following to be afull, clear,

. and exact description of the same.

Our invention relates to improvements in plugs used as wedges for dividinglarge stones in quarries; and the objects of our invention are, first, to lessen the'cost of quarrying implements and to secure a large advantage from the manual labor expended in parting or blocking-out stone blocks from the layers or strata formations. W'e attain these objects by means of the plug shown in the accompanying drawings, which illustrate our invention, and in which Figure 1 is a side view, and Fig. 2 a transverse section on line x m, Fig. 1, of our improved plug.

The present practice in quarrying is to use plugs in connection with iron or steel featherstrips, which are placed in the hole previously drilled in the rock, and then the plugis driven down between them, which has the effect of splitting the rock at this point. When it is desired to break off a straight face of considerable length, a number of holes are drilled in astraight line and plugs driven into them, which has the effect of splitting the rock in the direction of the line of holes.

For the proper working of these plugs in the rock there should be no pressure against those sides of the drill-hole which are in the line of fracture, the whole of the bursting force of the plug being in a direction at a right angle from the line of fracture. To this end the feat-her strips above mentioned areplaced on the outer and inner sides of the hole, so that the plug expands only in that direction. We attain this object without the use of featherstrips by means of our improved plug'A,which is tapered on all sides toward one end, but has two flat sides B, as shown in Fig. 2, extending from the point or smaller end up to near its larger end. This plug is placed in the drillhole, so that its flat sides will face the direction of fracture c c, and its resistance will be only from points at right angles from the line of fracture. From this it will be seen that by our improvement the labor of driving the plug is very much reduced,,as is also the cost of quarrying implements, by dispensing with the feather-strips.

Having thus described our invention, we claim as ours and desire to secure by Letters Patent A quarry-plug having rounded and flattened sides, respectively oppositely arranged, whereby the use of feather-strips is avoided, substantially as described.

Signed at Sherbrooke this 7th day of May, 1887.

MATTHEW BENTLEY. JOHN BENTLEY.

In presence of- D. O. RoBEETsoN, E. G. DAVIS, E. B. WORTHINGTON. 

